type fn = string list -> unit Lwt.tA function that takes a list of strings as argument and does some side effect.
A CLI command has a unique name, an optional help text that shows the usage, a description that gives background information and the actual CLI function.
Call run commands args in the main Sihl app executable to pass command line arguments to all registered commands. This is the main entry point to a Sihl app. An optional list of arguments args can be passed, if None is passed, it reads the arguments from Sys.argv.
val sexp_of_t : t -> Sexplib0.Sexp.tsexp_of_t t converts the command t to an s-expression
val pp : Stdlib.Format.formatter -> t -> unitpp formats the command t as an s-expression